Clinical features and the operative results in the author's personal series of ten cases with Nelson's syndrome are presented. There were nine females and one male patient with ages ranging from 20 to 44 years (mean 36 y). All patients presented with typical hyperpigmentation of the skin and had abnormally raised plasma ACTH levels. X-ray polytomography detected sellar abnormalities in 80% of the cases. Computerized tomography was positive for pituitary tumour in three patients. Trans-sphenoidal microsurgical removal of Nelson's ACTH adenomas were successful in seven of ten patients. The operative technique of radical-selective resection to achieve endocrinological cure is described. Pertinent literature is reviewed and the incidence of Nelson's syndrome, an issue of controversies regarding the pathogenesis, and the management of Nelson's adenomas are discussed.